/** Shared inference request identity headers. */
/** Options controlling provider and protocol inference headers. */
export interface InferenceHeaderOptions {
    provider: string;
    protocol: "anthropic" | "google" | "openai";
    sessionId?: string;
}
/** Set a header unless the map already contains that field under any casing. */
export declare function setHeaderIfAbsent(headers: Record<string, string>, name: string, value: string): void;
/**
 * Project omp's identity and authoritative conversation id onto the headers
 * understood by the active inference protocol and host.
 */
export declare function applyInferenceHeaders(headers: Record<string, string>, options: InferenceHeaderOptions): void;
/**
 * Return `init` with omp's process-wide inference User-Agent default applied.
 * Any explicit header, including Anthropic and Codex OAuth fingerprints,
 * remains authoritative. Called per request by `transportFetch`.
 *
 * Plain-object headers stay plain objects: custom `fetch` implementations
 * (proxies, tests) index `init.headers` by name and must not be handed a
 * `Headers` instance instead.
 */
export declare function withInferenceUserAgent(input: string | URL | Request, init: RequestInit | undefined): RequestInit | undefined;